卡氏肺孢子虫肺炎大鼠炎症反应及肺损伤研究

为研究卡氏肺孢子虫肺炎(PCP)大鼠炎症反应及肺损伤,通过皮下注射8～12周醋酸可的松免疫抑制诱导建立Sprague-Dawley大鼠PCP模型.将大鼠分为四组,Ⅰ组正常对照(n=6),为未用药的健康大鼠;Ⅱ组阴性对照(n=6),为无肺部感染的大鼠;Ⅲ组细菌性肺炎(n=11);Ⅳ组PCP(n=14).计数支气管肺泡灌洗液(BALF)中的细胞数并行分类,测定总蛋白(TP)、白蛋白(ALB)含量及碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)及Ⅳ型胶原酶(MMP-2、MMP-9)活性.比较PCP及细菌性肺炎其炎症反应及肺损伤的差别.PCP其BALF中细胞总数较阴性对照组增加(P《0.01),但低于细菌性肺炎组.PCP其BALF中白蛋白(622.5±484.0μg/ml)较阴性对照组增加(35.8±16.2 μg/ml,P《0.01).PCP其BALF中ALP及LDH活性(分别为217.0±81.4 U/L,20.8±8.2U/dl)也高于阴性对照组(P《0.01).PCP大鼠BALF中Ⅳ型胶原酶活性增加(P《0.001).PCP炎症发应不同于细菌性肺炎.在PCP,肺泡毛细血管膜通透性明显增加,存在明显肺损伤.

Study on Inflammatory Reaction and Lung Injury in Pneumocystis Carinii Pneumonia Rats

To study the inflammatory reaction and lung injury in pneumocystis carinii pneumonia(PCP), PCP was induced in Sprague-Dawley rats by the administration of cortisone acetate as immunosuppressant for 8-12 weeks. The Rats were divided ihto four groups, Group Ⅰ: normal control (n= 6), consisted of healthy rats without the steroid treatment; group Ⅱ: negative control (n = 6), rats free from lung infection;group Ⅲ: bacterial pneumonia (n=11); group Ⅳ (n=14): PCP . Cells in the bron choalveolar lavage fluid (BALF) were counted and differentiated, as well as the amounts of total protein (TP), albumin (ALB) and the activities of alkaline phos phatase (ALP), lactate dehydrogenase (LDH) and type Ⅳ collagenase (matrix metallco proteinases, MMP-2, MMP-9) were detected. And compared the differences in inflam matory reaction and lung injury between PCP and bacterial pneumonia . The total cell count in the BALF of PCP was significantly increased (P＜0.01), but was lower than that in the bacterial pneumonia group. ALB in the BALF of PCP (622. 5±484. 0μg/ml) was increased as compared with the negative controls (35.8±16. 2 μg/ml, P＜0.01). The activities of ALP and LDH in PCP (217.0±81.4u/L, 20. 8±8.2 u/dl respec tively) were also higher than those in the negative control (P＜0.01). The activities of Type Ⅳ collagenase were increased in PCP (P＜0.001). The inflammatory response in PCP differed from that found in bacterial pneumonia. The permeability of the alveolar capillary membrane and the lung injury were significantly increased in PCP.